This invention relates to a keyboard musical instrument and, more particularly, to a regulating button mechanism, a silent system cooperative therewith and a keyboard musical instrument.
A silent piano is fabricated on the basis of an acoustic piano, and is fallen within the scope of the keyboard musical instrument. The silent piano is a combination of an acoustic piano, a silent system and an electronic sound generating system. A standard upright piano or a standard grand piano is available for the silent piano. Therefore, a keyboard, action mechanisms, hammer assemblies, dampers and strings are incorporated in the acoustic piano.
The electronic sound generating system includes key/hammer sensors, a data processing system, a tone generator and a sound system. The key/hammer sensors monitor the keys and/or hammers, and supply key/hammer position signals representative of current key/hammer positions to the data processing system. The data processing system periodically checks the key/hammer position signals to see whether or not any one of the keys and hammers changes the current position from the previous position. If a key/hammer has changed the current position, the data processing system specifies the key/hammer, and determines the velocity. A key code assigned to the key/hammer and the velocity are stored in music data codes together with instructions, and the music data codes are supplied to the tone generator at appropriate timing. The tone generator produces an audio signal from the music data codes, and a headphone converts the audio signal to an electronic tones. Thus, the electronic sound generating system generates electronic tones in response to the fingering on the keyboard.
The silent system includes a hammer stopper provided between the hammer assemblies and the strings, and the hammer stopper is changed between a free position and a blocking position. When the hammer stopper is staying at the free position, the hammer stopper is out of the trajectories of the hammer assemblies, and the strings are selectively struck with the hammer assemblies in response to the fingering on the keyboard. The strings vibrate so as to generate piano tones. However, when the hammer stopper is changed to the blocking position, the hammer stopper is moved into the trajectories of the hammer assemblies. Although the escape of jacks give rise to free rotation of the hammer assemblies, the hammer assemblies rebound on the hammer stopper before striking the strings, and any piano tone is not generated through the vibrations of the strings. Thus, a pianist can practice the fingering without disturbance to the neighborhood, and the silent piano is popular to the pianists who live in downtown areas of cities.
Although the hammer stopper is simply moved between the free position and the blocking position, i.e., out of the trajectories of the hammer assemblies and on the trajectories of the hammer assemblies, it is not easy for the manufacturer to adjust the hammer stopper to the most appropriate position in the narrow space between the hammer assemblies and the strings. This is because of the fact that the jacks escape from the associated hammer assemblies at a short distance between the hammer assemblies and the strings. The escape points are adjusted by regulating the distance between the hammer assemblies and the strings to a predetermined value under the condition that a tuner slowly depresses the associated keys. The predetermined value is of the order of 2 milliters in standard grand pianos. This means that the manufacturer is to install the hammer stopper in the extremely narrow space accurately. If the hammer stopper is too close to the hammer assemblies at the rest positions, the hammer assemblies are pinched between the jacks and the hammer stopper in the blocking position before the escape.
It is effective against the pinch to make the time to escape from the hammers earlier than usual. The escape takes place when the toe of the jack is brought into contact with the regulating button. The time to escape from the hammer is made earlier by decreasing the distance between the toe and the regulating button. However, the escape deeply concerns key touch unique to the acoustic piano. If the manufacturer advances the escape from the usual timing, the unique piano key touch is destroyed. For this reason, the regulation of the escape time is less desirable.
A tandem regulating button mechanism was proposed in order to change the escape point depending upon the position of the hammer stopper. FIG. 1 shows the prior art tandem regulating button mechanism. In FIG. 1, the xe2x80x9cfrontxe2x80x9d is the right side, and the xe2x80x9crearxe2x80x9d is the left side. A key, an action mechanism, a hammer assembly, a string and a tandem regulating button mechanism 5 are labeled with reference numerals 1, 2, 3, 4 and 5, respectively. The action mechanism 2 is held in contact with the key 1 by means of a capstan screw 2a, and the hammer assembly 3 is driven for free rotation by the action mechanism 2. The action mechanism 2, the hammer assembly 3 and the tandem regulating button mechanism 5 are supported by action brackets 6a, and, accordingly, the action mechanism 2, the hammer assembly 3 and the tandem regulating button mechanism 5 assembled with the action brackets are hereinbelow referred to as xe2x80x9caction bracket assemblyxe2x80x9d.
The action mechanism 2 includes a whippen flange 2b, a whippen assembly 2c, a jack 2d, a repetition lever 2e and a repetition spring 2f The whippen flange 2b is fixed to a whippen rail 2g, which is supported by the action brackets 6a. The whippen assembly 2c is rotatably connected to the whippen flange 2b at the rear end thereof, and forwardly projects from the whippen flange 2b. The jack 2d has an L- letter shape, and has a leg portion 2h and a foot portion 2j. The jack 2d is rotatably connected at a bend portion to the front end portion of the whippen assembly 2c, and the leg portion 2h is inserted into a hole formed in the repetition lever 2e. A toe 2k and a bump 2m are formed in the foot portion 2j, and the bump 2m is closer to the bent portion than the toe 2k . 
The prior art tandem regulating button mechanism 5 includes a regulating rail 5a, a plurality of first regulating buttons 5b, a plurality of second regulating buttons 5c and a shaft 5d. A shank flange rail 6b is supported by the action brackets 6a, and the regulating rail 5a is screwed to the shank flange rail 6b. The first regulating buttons 5b are hung from the regulating rail 5a, and are directed to the toes 2k of the associated jacks 2d. Each of the first regulating buttons 5b is rotatable around the center axis of a screw 5e so as to vary the gap between the toe 2k and the lower end surface thereof. On the other hand, the second regulating buttons 5c are connected to the shaft 5d by means of screws 5f, and the shaft 5d is rotatably supported by the action brackets 6a. The shaft 5d is connected to a driving mechanism (not shown), and the second regulating buttons 5c are swingable around the center axis of the shaft 5d. The second regulating buttons 5c are changed between the first angular position and the second angular position. When the hammer stopper 7 is changed to the free position, the second regulating buttons 5c are changed to the first angular position, and are moved out of the trajectory of the bump 2m. On the other hand, when the hammer stopper 7 is changed to the blocking position, the second regulating buttons 5c are changed to the second angular position, and the second regulating buttons 5c are moved into the trajectory of the bump 2m. The prior art tandem regulating button mechanism is advantageous in that the jack 2d escapes from the hammer assembly 3 at different speed between the two modes of operation. The toe 2k and the bump 2m are concurrently brought into contact with the first regulating button 5b and the second regulating button 5c, and the jack starts the escape at the same timing. However, the bump 2m and the second regulating button 5c give rise to the rotation of the jack 2d at higher speed. Because, the reaction at the bump 2m causes the jack 2d to turn over a larger angle. This results in early completion of the escape. For this reason, the hammer assembly 3 is less pinched between the jack 2d and the hammer stopper 7. Thus, the prior art tandem regulating button mechanism is effective against the hammer assembly 3 pinched between the jack 2d and the hammer stopper 7 without destruction of the unique piano key touch. However, a tuner feels it complicated to adjust the prior art tandem regulating button mechanism to the optimum escape timing. This is because of the fact that the tuner needs repeatedly moving the action bracket assembly from and onto the key bed. In detail, the escape takes place when the toe 2k or the bump 2m is brought into contact with the associated regulating buttons 5b/5c, and, accordingly, the gap between the toe/bump 2k/2m and the first/second regulating buttons 5b/5c deeply concerns the escape of the jack. The tuner rotates the first regulating button 5b around the screw 5e so that the first regulating button 5b projects from or is retracted into the screw 5e. Accordingly, the gap between the toe 2k and the first regulating button 5b is varied together with the movement of the first regulating button 5b. The tuning is carried out without moving the action bracket assembly. The tuner rotates the screw 5f around the centerline thereof so as to space the second regulating button 5c from or draw the second regulating button 5c near the shaft 5d. Accordingly, the gap between the bump 2m and the second regulating button 5c is varied together with the movement of the second regulating button 5c. The screw 5f is located in the narrow space among the components of the action mechanism 2, and the second regulating button 5c is provided under the shaft 5d. It Is impossible for the tuner to regulate the gap with the action bracket assembly leaving on the key bed. For this reason, the tuner moves the action bracket assembly from the key bed to a working table, and regulates the gap. However, the tuning work is incomplete. The tuner checks the gap between the hammer assembly 3 and the string 4 by slowly depressing the associated key 1 to see whether or not the hammer assembly 3 is disengaged with the jack 2d at an appropriate point. In order to measure the gap between the hammer assembly 3 and the string 4, the tuner moves the action bracket assembly from the working table onto the key bed. The tuner repeats the works until the second regulating button 5c is appropriately tuned. Thus, the tuning works are complicated and time-consuming. This is the problem inherent in the prior art tandem regulating button mechanism.
It is therefore an important object of the present invention to provide a regulating button mechanism, which is easily accurately regulated to optimum escape timing.
It is also an important object of the present invention to provide a silent system, which includes the regulating button mechanism.
It is another important object of the present invention to provide a keyboard musical instrument, which is equipped with the regulating button mechanism.
To accomplish the object, the present invention proposes to.
In accordance with one aspect of the present invention, there is provided a regulating mechanism associated with a jack incorporated in an action mechanism forming a part of a keyboard musical instrument, and the regulating mechanism comprises a regulating member provided for the jack so as to permit the jack to escape from a beating member of the keyboard musical instrument when the jack is brought into contact with the regulating member, a supporting member connected to a stationary member of the keyboard musical instrument, a retainer connected to the regulating member and movably supported by the supporting member and an adjusting mechanism connected between the supporting member and the retainer for changing a relative position between the supporting member and the retainer and having a manipulator projecting into a free space formed in the keyboard musical instrument and manipulated by a tuner for changing a gap between the regulating member and the jack through a relative motion between the retainer and the supporting member.
In accordance with another aspect of the present invention, there is provided a silent system incorporated in a keyboard musical instrument having plural keys, plural action mechanisms respectively connected to the plural keys and arranged in a lateral direction and plural beating members respectively actuated by the plural action mechanisms through first escapes of jacks forming parts of the plural action mechanism for striking plural vibratory members when first portions of the plural jacks are brought into contact with a primary regulating member, and the silent system comprises a stopper provided for the plural beating members and changed between a free position provided out of trajectories of the plural beating members for permitting the plural beating members to strike the plural vibratory members and a blocking position provided on the trajectories for causing the plural beating members to rebound thereon before striking the plural vibratory members, a secondary regulating member changed between an active position provided on trajectories of second portions of the plural jacks and related to the blocking position and an inactive position provided out of the trajectories of the second portions and related to the free position and producing second escapes faster than the first escapes when the second portions are brought into contact therewith, a supporting member provided in the vicinity of the secondary regulating member and connected to a stationary member of the keyboard musical instrument, a retaining member connected to the secondary regulating member and movably supported by the supporting member and an adjusting mechanism connected between the supporting member and the retaining member for changing a relative position between the supporting member and the retaining member and having a manipulator projecting into a free space formed in the keyboard musical instrument and manipulated by a tuner for varying a distance between the second portions and the secondary regulating member through changing the relative position.
In accordance with yet another aspect of the present invention, there is provided a keyboard musical instrument having a fore-and-aft direction and a lateral direction perpendicular to the fore-and-aft direction comprising a keyboard having plural keys selectively moved by a player positioned in front of the keyboard, plural action mechanisms provided over a rear portion of the keyboard so as to create a free space over a front portion of the keyboard, connected to the keys so as to be selectively actuated by the moved keys and having jacks and a primary regulating member for producing first escapes of the jacks when first portions of the jacks are brought into contact with the primary regulating member, plural beating members respectively driven for rotation by the plural action mechanisms when the first escapes or second escapes are produced, plural vibratory members respectively struck with the plural beating members at the end of the rotation, a secondary regulating member opposed to second portions of the jacks and producing the second escape when the second portions are brought into contact therewith, a supporting member connected to a stationary member, a retaining member connected to the secondary regulating member and movably supported by the supporting member so as to change a relative position therebetween, and an adjusting mechanism connected between the secondary regulating member and the supporting member for changing the relative position and having a manipulator projecting into the free space and manipulated for changing a distance between the second portions and the secondary regulating member by changing the relative position.